Cancer, Cell Death, and Stem Cells

Question 1

Compare apoptosis and necrosis

Answer 1

Apoptosis:
programmed
leads to cell elimination without release of harmful substances

Necrosis:
uncontrolled
response to lethal injury
leads to damage in cell and to tissue containing it

Question 2

What are stem cells? What are they used for?

Answer 2

unspecialized cells
potential to differentiate into any type of cell
in human embryos, umbilical cord blood and some adult cells
used to repair injuries in brain and spine, cure some diseases (like diabetes), and replace organs as liver tissue and heart valves

Question 3

Describe the structure of a virus

Answer 3

non cellular; infectious
made of DNA or RNA and protein coat
replicates after its genetic material enters host cells
subverts metabolic structures

Question 4

Describe viral replication

Answer 4

virus reproduces itself in living organism
turns infected cells into virus factories
turns infected body against itself; uses its own tools for mass production and infection

Question 5

Describe cancer

Answer 5

disorder where some cells lose their ability to control growth
cancer cells don’t respond to growth control signals
form masses called tumors that can damage surrounding tissues
stop growing when supply of nutrients is used up
cancerous cells can break off from tumors and spread